YAG Laser comes in 2 wavelengths, 1064 nm and 532 nm. It is a non-ablative laser, which means that there is no break in skin tissue continuity during the treatment. It is designed to target pigment cells. This specific wavelength are absorbed preferentially by pigments (melanin) and the resultant heat will cause generation and propagation of waves that cause damage to the cells containing pigment. These damaged cells will then be cleared from the site resulting in lightening of the pigmented site.